Paint mediums and varnishes serve distinct purposes in the world of art and painting.

Paint Mediums:

Paint mediums are substances added to paint to alter its consistency, drying time, texture, finish, or transparency. They can also enhance the paint's workability, adhesion, and durability. Some common types of paint mediums include:

Acrylic Mediums:

Used with acrylic paints to modify their characteristics. Examples include:

Retarders: Slow down drying time.
Gel mediums: Alter texture and thickness.
Matte or Gloss Varnishes: Change the finish of the paint.

Oil Mediums:

Used with oil paints to control drying time and enhance characteristics like transparency or glossiness. Examples include:

Linseed oil: Commonly used to extend colors and add gloss.
Stand oil: Slower drying time, increases flow, and gloss.
Turpentine or Mineral Spirits: Thinning agents.

Watercolor Mediums:

These can include masking fluid, gum arabic (to enhance transparency), or ox gall (to improve flow and wetting properties).

Gouache Mediums:

Often mixed with water to adjust opacity or to extend the paint.

Varnishes:

Varnishes are applied as a protective layer over completed paintings to enhance the appearance and provide protection against environmental factors. Different types of varnishes include:

Acrylic Varnish: Ideal for acrylic paintings. Available in gloss, satin, or matte finishes.

Oil Varnish: Used for oil paintings. Dries to a hard, glossy finish, enhancing colors and protecting the painting.

Spray Varnish: Available for both acrylic and oil paintings. Provides an even and thin layer of protection.

Damar Varnish: Commonly used for its high gloss and traditional properties. Used mainly with oil paintings.

How They're Used:

Mixing: Paint mediums are added directly to paint on a palette to modify its properties.

Application:

Varnishes are typically applied as a final protective layer once the painting is completely dry (which can take weeks to months depending on the paint used).

Techniques:

Various techniques like glazing, impasto, or extending paint can be achieved using different mediums.

Considerations:

Always ensure compatibility between the medium/varnish and the type of paint used.
Follow manufacturer instructions for proper usage and proportions.

Consider ventilation and safety precautions, especially with mediums containing solvents.

Understanding these mediums and varnishes allows artists to manipulate their paints to achieve desired effects, protect their artworks, and explore different techniques in their creative process.